All species on Earth occupy limited geographic space. More than a century of observational, experimental, and theoretical work investigating the factors that drive species distributions have demonstrated the importance of the interactions between abiotic, biotic, and demographic factors in determining why species are found where they are. However, it is still unclear when and where these factors interact to set species range limits. Filling the existing knowledge gaps is imperative for the accurate predictions of how species will respond to global change, and particularly for invasive species, many of which are expected to benefit from global change. Here, I sought to investigate the mechanisms that enable, as well as limit, the range expansion of the globally invasive plant Sorghum halepense (L.) Pers. (Johnsongrass). I performed a series of field and laboratory experiments to study population and range dynamics throughout Johnsongrass's North American distribution, and test for the effects of climate, local habitat, and competition on multiple functional traits. I found Johnsongrass consistently demonstrated impressive performance across varying environments, often growing more than 3 m tall, producing hundreds of flowering culms within a single growing season, and maintaining positive population growth rates, even under intense competition with resident weeds. I also found evidence that seed germination has adapted to varying climates encountered during Johnsongrass's range expansion resulting in a shift in the germination temperature niche from warmer to cooler as Johnsongrass spread from warmer climates in the south to more temperate climates in higher latitudes. This shift in the germination temperature niche may have been an important contributing factor in the range expansion of Johnsongrass by enabling the optimization of seed germination in varying climates. On the other hand, results from a field study suggested a possible trade-off between flowering time and growth in populations originating from the range periphery (i.e., range boundary) which may be limiting, or slowing, continued range expansion of Johnsongrass. Together, the outcomes of this work contribute to our understanding of the factors involved in the distribution of species, which is a fundamental goal of Ecology, and essential to accurately predict how invasive species will respond to global change. / Doctor of Philosophy / Invasive species threaten our natural ecosystems, our agricultural systems, and even our infrastructure, and we spend billions of dollars each year attempting to control them and reduce their negative impacts. Climate change, habitat destruction, and other forms of global change, will benefit many of these species, magnifying their impacts and promoting their invasion into new territories. Because of the damaging effects of invasive species, and the costs to control them, it is imperative that we are able to predict how they will respond to global change so that we can improve plans to reduce their impact and spread. First, we need to understand the processes that promote their invasion across large swaths of land. Just as importantly, we must study the processes that prevent their invasion of certain areas. Here, I investigated some of the processes that have facilitated, as well as hampered, the spread of the invasive plant Johnsongrass. For this work, I used Johnsongrass plants originating from different habitats, including regions where Johnsongrass is highly invasive and those where Johnsongrass is very rare. I found Johnsongrass originating from regions where it is highly invasive were able to grow very large and produce thousands of seeds that were able to germinate under a range of conditions. These traits may have contributed to the invasion success of this species. However, I found a different pattern for plants that originated from regions where Johnsongrass is rare. These plants reached reproductive age earlier and grew smaller across all environmental conditions, potentially due to the less hospitable climates of these range edges. These findings allow us to project into future climate change scenarios, because it is likely that, as temperatures warm, invasive species will be able to invade new regions, where they will impact the work of conservationists, natural resource professionals, agricultural produces, and other land managers.

Conventional and unconventional reservoirs are both critical in oilfield developments. After waterflooding treatments over decades, the petrophysical properties of a conventional reservoir may change in many aspects. It is crucial to identify the variations of these petrophysical properties after the long-term waterflooding treatments, both at the pore and core scales. For unconventional reservoirs, the productivity and performance of hydraulic fracturing in shales are challenging because of the complicated petrophysical properties. The confining pressure imposed on a shale formation has a tremendous impact on the permeability of the rock. The correlation between confining pressure and rock permeability is complicated and might be nonlinear. In this thesis, a series of laboratory tests was conducted on core samples extracted from four U.S. shale formations to measure their petrophysical properties. In addition, a special 2D microfluidic equipment that simulates the pore structure of a sandstone formation was developed to investigate the influence of injection flow rate on the development of high-permeability flow channels. Moreover, the multiple linear regression (MLR) model was applied with the predictors based on the development stages to quantify the variations of reservoir petrophysical properties. The MLR model outcome indicated that certain variables were effectively correlated to the permeability. The 2D microfluidic model demonstrated the development of viscous fingering when the injection water flow rate was higher than a certain level, which resulted in reduced overall sweep efficiency. These comprehensive laboratory experiments demonstrate the role of confining pressure, Klinkenberg effect, and bedding plane direction on the gas flow in the nanoscale pore space in shales. / Master of Science / Conventional and unconventional hydrocarbon reservoirs are both important in oil-gas development. The waterflooding treatment is the injection of water into a petroleum reservoir to increase reservoir pressure and to displace residual oil, which is a widely used enhanced oil recovery method. However, after waterflooding treatments for several decades, it may bring many changes in the properties of a conventional reservoir. To optimize subsequent oilfield development plans, it is our duty to identify the variations of these properties after the long-term waterflooding treatments, both at the pore and core scales. In unconventional reservoirs, hydraulic fracturing has been widely used to produce hydrocarbon resources from shale or other tight rocks at an economically viable production rate. The operation of hydraulic fracturing in shales is challenging because of the complicated reservoir pressure. The external pressure imposed on a shale formation has a tremendous impact on the permeability of the rock. The correlation between pressure and rock permeability is intricate. In this thesis, a series of laboratory tests was conducted on core samples to measure their properties and the pressure. Moreover, a statistical model was applied to quantify the variations of reservoir properties. The results indicated that certain reservoir properties were effectively correlated to the permeability. These comprehensive investigations demonstrate the role of pressure, special gas flow effect, and rock bedding direction on the gas flow in the extremely small pore in shales.

End-of-life lithium-ion batteries retired from portable electronics, electric vehicles (EVs), and power grids need to be properly recycled to save rare earth metals and avoid any hazardous threats to the environment. The recycling process of a Lithium-ion Battery Cell/Module includes storage, transportation, deactivation, disassembly, and material recovery. This study focused on the disassembly step and proposed a systematic method to recover cathode active coating, which is considered the most valuable component of a LIB, from end-of-life LIB pouch cells. A semi-destructive disassembly sequence is developed according to the internal structure of the LIB cell. A fully automated disassembly line aiming at extracting cathode electrodes is designed, modeled, prototyped, and demonstrated based on the disassembly sequence. In order to further obtain the coating material, the extracted cathode electrodes are treated with the organic solvent method and the relationship between process parameters and cathode coating separation yield is numerically studied with the help of Design of Experiment (DOE). Regression models are then fitted from the DOE result to predict the cathode coating separation yield according to combinations of the process parameters. The single cell material separation methodology developed in this study plays an important role in the industrial application of the direct recycling method that may dominate the battery recycling market due to its environmental friendly technology and high recovery rate regardless of element type in the short future. / Doctor of Philosophy / The bursting demand of lithium-ion batteries from portable electronics, electric vehicles, and power grids in the past few years not only facilitate the booming of the lithium-ion battery market, but also put forward serious global concerns: Where should these batteries go at their end-of life and how should they be treated in a safe and harmless manner. As a metal enriched "city mine", end-of-life LIBs are expected to be properly stored, transported, deactivated, disassembled, and recovered with sufficient safety precautions to prevent fire, explosion or any hazardous emissions. This study focuses on the disassembly procedure and emphasized automated battery disassembly techniques and the improving of material separation efficiency. A disassembly sequence of the pouch cell is scheduled and optimized for the first time. To realize the scheduled sequence, a fully automated pouch cell disassembly system is designed to achieve semi-destructive disassembly of z-folded pouch cells. Fixtures, transporters and end-effectors were prototyped and assembled into the modularized disassembly line which extracts cathode electrodes as final product. Cathode electrodes as the most valuable component in a LIB then need to go through multiple chemical-mechanical treatments to future separate cathode coating and Al current collector. This study utilized DOEs to optimize the operating parameters of the material separation process for Lithium cobalt oxide (LCO) coating and Lithium iron phosphate (LFP) coating. Regression models are successfully established for yield prediction with certain levels of control factors.

Yes / This paper isolates litter as a physical incivility in a film-based experiment, demonstrating the impact of litter on participants' anticipation of a wide range of both physical and social incivilities, and on their perceptions of crime prevalence. Such relationships have not previously been examined, partly because litter has rarely been the focus of earlier studies on incivilities. This paper also tests for possible interaction effects in these relationships involving gender (finding no significant interaction), as well as examining whether there is a difference in the anticipation of incivilities and perceptions of crime prevalence between participants exposed to branded as opposed to unbranded litter (finding no difference between the two groups). Litter is often viewed as a tolerable nuisance and not always treated as a priority. This study suggests prioritising funds towards more targeted interventions to reduce litter might result in some ‘quick wins’ – most notably, reducing perceptions of crime prevalence. / The full text will be available at the end of the publishers embargo: 1st March 2018.

The response surface problem is two-fold: to predict values of the response, and to optimize the response. Slope estimation criteria are well suited for the optimization problem. Response prediction capability has been assessed by plotting the average, maximum, and minimum prediction variances on the surface of spheres with radii ranging across the region of interest. Average and maximum prediction bias plots have recently been added to the spherical criteria. Combined with the prediction variance, a graphical MSE criterion results. This research extends these ideas to the slope estimation objective. A direct relationship between precise slope estimation and the ability to pinpoint the location of the optimum is developed, resulting in a general slope variance measure related to E-optimality in slope estimation. A more specific slope variance measure is defined and analyzed for use in evaluating standard response surface (RS) designs,where slopes parallel to the factor axes are estimated with equal precision. Standard second order RS designs are then studied in light of the prediction and optimization goal distinction. Designs which perform well for prediction of the response do not necessarily estimate the slope precisely. A spherical measure of bias in slope estimation is developed and used to measure slope bias due to model misspecification and due to the presence of outliers. A study of augmenting saturated orthogonal arrays of strength two to detect lack of fit is included as an application of a combined squared bias and variance measure of MSE in slope. A study of the designs recommended for precise slope estimation in their robustness to outliers and to missing observations is conducted using the slope bias and general slope variance measures, respectively. / Ph. D.

Sequential experimentation, especially for factorial treatment structures, becomes important when one or more of the following, conditions exist: observations become available quickly, observations are costly to obtain, experimental results need to be evaluated quickly, adjustments in experimental set-up may be desirable, a quick screening of the importance of various factors is important. The designs discussed in this study are suitable for these situations. Two approaches to sequential factorial experimentation are considered: one-run-at-a-time (ORAT) plans and one-block-at-a-time (OBAT) plans. For 2ⁿ experiments, saturated non-orthogonal 2ᵥⁿ fractions to be carried out as ORAT plans are reported. In such ORAT plans, only one factor level is changed between any two successive runs. Such plans are useful and economical for situations in which it is costly to change simultaneously more than one factor level at a given time. The estimable effects and the alias structure after each run have been provided. Formulas for the estimates of main-effects and two-factor interactions have been derived. Such formulas can be used for assessing the significance of their estimates. For 3^m and 2ⁿ3^m experiments, Webb's (1965) saturated non-orthogonal expansible-contractible <0, 1, 2> - 2ᵥⁿ designs have been generalized and new saturated non-orthogonal expansible-contractible 3ᵥ^m and 2ⁿ3ᵥ^m designs have been reported. Based on these 2ᵥⁿ, 3ᵥ^m and 2ⁿ3ᵥ^m designs, we have reported new OBAT 2ᵥⁿ, 3ᵥ^m and 2ⁿ3ᵥ^m plans which will eventually lead to the estimation of all main-effects and all two-factor interactions. The OBAT 2ⁿ, 3^m and 2ⁿ3^m plans have been constructed according to two strategies: Strategy I OBAT plans are carried out in blocks of very small sizes, i.e. 2 and 3, and factor effects are estimated one at a time whereas Strategy II OBAT plans involve larger block sizes where factors are assumed to fall into disjoint sets and each block investigates the effects of the factors of a particular set. Strategy I OBAT plans are appropriate when severe time trends in the response may be present. Formulas for estimates of main-effects and two-factor interactions at the various stages of strategy I OBAT 2ⁿ, 3^m and 2ⁿ3^m plans are reported. / Ph. D.

A parameter design introduced by Taguchi provides a new quality control method which can reduce cost-effectively the product variation due to various uncontrollable noise factors such as product deterioration, manufacturing imperfections, and environmental factors under which a product is actually used. This experimental design technique identifies the optimal setting of the control factors which is least sensitive to the noise factors. Taguchi’s method utilizes orthogonal arrays which allow the investigation of main effects only, under the assumption that interaction effects are negligible. In this paper new techniques are developed to investigate two-factor interactions for 2^t and 3^t factorial parameter designs. The major objective is to be able to identify influential two-factor interactions and take those into account in properly assessing the optimal setting of the control factors. For 2^t factorial parameter designs, we develop some new designs for the control factors by using a partially balanced array. These designs are characterized by a small number of runs and some balancedness property of the variance-covariance matrix of the estimates of main effects and two-factor interactions. Methods of analyzing the new designs are also developed. For 3^t factorial parameter designs, a detection procedure consisting of two stages is developed by using a sequential method in order to reduce the number of runs needed to detect influential two-factor interactions. In this paper, an extension of the parameter design to several quality characteristics is also developed by devising suitable statistics to be analyzed, depending on whether a proper loss function can be specified or not. / Ph. D.

Contentious interactions may arise between a tax professional and client upon a disagreement over a tax position. In an increasingly competitive tax return preparation market, these contentious interactions represent a significant threat to tax practitioners' client satisfaction and retention objectives. I conduct an experiment in which I examine the effect of three factors on tax clients' (1) likelihood to accept the advice of the tax accountant and (2) likelihood to switch tax accountants upon receiving professional advice counter to their preferred tax position. The three factors are: (1) clients' antagonistic narcissism; (2) clients' relationship with the accountant; and (3) how the advice is framed by the tax accountant. The results are based on a sample of 93 taxpayers. First, this study examines how clients' measured levels of narcissistic antagonism (hereafter, antagonism) impacts their reaction to "being told no" by their tax professional. Results indicate that upon the receipt of advice contrary to their preferences, highly antagonistic clients are more likely to (1) engage in a contentious interaction with their professional and (2) switch to a new tax professional. Supplemental path analyses document that individuals with high levels of antagonism cognitively react to instances of "being told no" by simultaneously devaluing their professionals' credibility and role as a client advocate, leading to these aggressive behaviors. This study also examines how the social closeness of the professional-client relationship influences the argue and switch decisions. Multivariate analysis indicates that social closeness is significantly related to the argue and switch decision. However, univariate results do not show significant relationship between social closeness and each of the decisions individually. That is, I find partial support for the professional publications and AICPA recommendations that tax practitioners should develop personal relationships with their clients to improve client satisfaction and likelihood of retention. Clients are marginally more likely to retain their current tax professional for future years when they feel they have a personal relationship with their tax practitioner, as opposed to those in a purely professional relationship. Finally, this dissertation considers the manner in which a tax professional frames his/her advice that is counter to a client's preferences. Results indicate that contrary advice that focuses on the potential downsides of an aggressive tax position (e.g., IRS audits and penalties) significantly dissuades client argument with the professional and significantly deters switching to a new tax accountant as compared to advice that is framed as being in the clients' "best interest."

Die Dissertation beschäftigt sich mit der Kommunikation der beiden Energie-Technologien Wasserstoff und Offshore-Wind und untersucht, inwieweit konkrete Argumente in der Lage sind, deren Akzeptanz intendiert zu beeinflussen. Um die Wirkung von sowohl positiven als auch negativen Argumenten zu messen, wurde ein repräsentativ angelegtes Experiment durchgeführt. Die Auswahl der dort getesteten Argumente basiert auf zwei Basis-Studien, mit deren Hilfe Argumente identifiziert wurden, welche Akteure aus den Bereichen Wirtschaft, Politik, Forschung, Gesellschaft und Medien in ihrer Kommunikation nutzten: (1) Systematische Dokumentenanalyse von Kommunikationsmaterial und (2) Quantitative Medienanalyse von Nachrichtenmedien für 2009 und 2013. Dabei wurde das Ziel verfolgt, für jedes der fünf Akteurssysteme sowohl häufig (dominante) als auch selten verwendete Argumente (Reframes) aufzuspüren, um die Wirkung beider Argument-Typen zu untersuchen. Die Effekte von Argumenten auf die Akzeptanz wurden sowohl unmittelbar erfasst als auch nach einer Zeitspanne von 3 Wochen, was – durch ein Panel-Design umgesetzt – auch Aussagen über die Wirkungsdauer lieferte. Zudem wurde analysiert, inwieweit der Persuasionsprozess durch bestimmte Moderatoren beeinflusst wird: Emotionalisierung, Competitive Framing, Persönliche Betroffenheit von einer Technologie, Art der Informationsverarbeitung und Zeitpunkt der Urteilsbildung. Die Studie konnte für beide Energie-Technologien eine stärkere Wirkung dominanter Argumente im Vergleich zu Reframes feststellen. Reframes sollten deshalb in der Kommunikation nur dann verwendet werden, wenn das Argument bereits einen gewissen Bekanntheitsgrad erzielt hat. Emotionalisierung wirkte nur bedingt: Insbesondere positive Reframes sowie negative dominante Argumente konnten emotionalisiert die Akzeptanz stärker beeinflussen. Zudem wurde das NIMBY-Konzept relativiert: Besonders von einer Technologie persönlich Betroffene wurden von positiven Argumenten überzeugt – negative Argumente entfalteten ihre Wirkung dagegen eher bei Nicht-Betroffenen. Weiterhin ließen sich die Annahmen der klassischen Zwei-Prozess-Modelle der Informationsverarbeitung entkräften, da auch die in dieser Studie fokussierten inhaltlichen Argumente heuristisch verarbeitet wurden und Wirkung erzielten.

Counter-Current Flow Limitation (CCFL) is of importance for PWR safety analyses in several accident scenarios connected with loss of coolant. Basing on the experiences obtained during a first series of hot leg tests now new experiments on counter-current flow limitation were conducted in the TOPFLOW pressure vessel. The test series comprises air-water tests at 1 and 2 bar as well as steam-water tests at 10, 25 and 50 bar. During the experiments the flow structure was observed along the hot leg model using a high-speed camera and web-cams. In addition pressure was measured at several positions along the horizontal part and the water levels in the reactor-simulator and steam-generator-simulator tanks were determined. This report documents the experimental setup including the description of operational and special measuring techniques, the experimental procedure and the data obtained. From these data flooding curves were obtained basing on the Wallis parameter. The results show a slight shift of the curves in dependency of the pressure. In addition a slight decrease of the slope was found with increasing pressure. Additional investigations concern the effects of hysteresis and the frequencies of liquid slugs. The latter ones show a dependency on pressure and the mass flow rate of the injected water. The data are available for CFD-model development and validation.